SPIN legend Muttiah Muralidaran has taken aim at Australian selection boss John Inverarity over the doosra debate, saying critics who believe the controversial delivery cannot be bowled legally are "narrow-minded".

Ahead of the first Test between Australia and Sri Lanka, starting tomorrow, Muralidaran spoke of his frustration at ill-informed critiques and offered to teach off-spinner Nathan Lyon the mystery ball to prove it can be bowled without a chucking action.

Inverarity, Australia's chairman of selectors, said Cricket Australia faced a "question of integrity" when asked at a recent MCG luncheon if the nation's spinners should be educated on how to bowl the doosra.

The 68-year-old qualified the comment by adding he was not opposed to the delivery, which turns from leg to off for the right-arm finger spinner, provided it is taught and executed within the ICC's bowling laws.

Muralidaran was subjected to years of condemnation over the bona fides of the doosra and says he is fed-up with leading cricket identities questioning its legality.

"If he (Inverarity) thinks that ... anyone who says you can't bowl the doosra legally is narrow-minded," Muralidaran fired.

"If Australia feels that way, they will never be able to bowl it.

"Why is it possible that bowlers in India, Sri Lanka, Pakistan and Bangladesh can bowl the doosra? Why can't the Australian bowlers do it?

"There are a few ways of bowling the doosra to send it the other way. Nathan Lyon could bowl it. If he learned to bowl the ball the other way, he would be more attacking and he will get more wickets.

"Who can say that it can't be done if they haven't tried it? In this world, if you work hard and train hard you can achieve things.

"If you have that mindset that it can't be done, well bad luck."

Inverarity said of the doosra: "It's a serious issue. I'm all for them (Australian spinners) learning it, but it's got to be within the rules. I think the integrity of the game and the integrity of our Australian cricket heritage is important.

"I'd love to see someone bowling differently, but we'd scrutinise them to make sure they're bowling properly."

Muralidaran said the degree of flexion is irrelevant in bowling the doosra.

"It's not about flexion," he said. "If you read the biomechanics reports, flexion is hard to tell, you can't see it accurately because everyone bowler flexes. Glenn McGrath used to flex more than 10 degrees, so people have got the wrong idea.

"There needs to be education about the doosra. People think because of more flexion you can bowl the doosra ... no you can't, it's an art.

"You have to train, you have to learn how to send the ball the other way around.

"I know how to do it, I can teach it to Australian bowlers, but it takes about one or two years to bowl it.

"It won't come in two days. The problem is some bowlers don't want to put in the hard work."